Diffusion in Silicon. III. Generation of Excess Vacancies at Climbing Diffusion-Induced Dislocations, and Dislocation-Enhanced Diffusion in (001) Crystals

Abstract

In Part I a simple dislocation‐enhanced diffusion model was proposed to explain the anomalous diffusion of phosphorus and boron in (111)‐oriented silicon crystals. Consideration was given to jogs created by dislocation intersections which undergo climb and emit vacancies as they are carried into the crystal on gliding diffusion‐induced dislocations, and it was shown that this can result in a considerably increased rate of impurity diffusion. We show here that a significant contribution to the total vacancy concentration is also produced by the emission of vacancies by climbing diffusion‐induced dislocations. This contribution also results in a considerable increase in the rate of diffusion. The results are extended to the case of diffusion in (001) crystals in which the mechanisms of dislocation propagation are different. It is shown that the mechanisms of vacancy generation at dislocations operate with approximately equal efficiency in (001) and (111) crystals.